1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __NET_SCHED_GENERIC_H 3 #define __NET_SCHED_GENERIC_H 4 5 #include <linux/netdevice.h> 6 #include <linux/types.h> 7 #include <linux/rcupdate.h> 8 #include <linux/pkt_sched.h> 9 #include <linux/pkt_cls.h> 10 #include <linux/percpu.h> 11 #include <linux/dynamic_queue_limits.h> 12 #include <linux/list.h> 13 #include <linux/refcount.h> 14 #include <linux/workqueue.h> 15 #include <net/gen_stats.h> 16 #include <net/rtnetlink.h> 17 18 struct Qdisc_ops; 19 struct qdisc_walker; 20 struct tcf_walker; 21 struct module; 22 23 struct qdisc_rate_table { 24 struct tc_ratespec rate; 25 u32 data[256]; 26 struct qdisc_rate_table *next; 27 int refcnt; 28 }; 29 30 enum qdisc_state_t { 31 __QDISC_STATE_SCHED, 32 __QDISC_STATE_DEACTIVATED, 33 }; 34 35 struct qdisc_size_table { 36 struct rcu_head rcu; 37 struct list_head list; 38 struct tc_sizespec szopts; 39 int refcnt; 40 u16 data[]; 41 }; 42 43 /* similar to sk_buff_head, but skb->prev pointer is undefined. */ 44 struct qdisc_skb_head { 45 struct sk_buff *head; 46 struct sk_buff *tail; 47 __u32 qlen; 48 spinlock_t lock; 49 }; 50 51 struct Qdisc { 52 int (*enqueue)(struct sk_buff *skb, 53 struct Qdisc *sch, 54 struct sk_buff **to_free); 55 struct sk_buff * (*dequeue)(struct Qdisc *sch); 56 unsigned int flags; 57 #define TCQ_F_BUILTIN 1 58 #define TCQ_F_INGRESS 2 59 #define TCQ_F_CAN_BYPASS 4 60 #define TCQ_F_MQROOT 8 61 #define TCQ_F_ONETXQUEUE 0x10 /* dequeue_skb() can assume all skbs are for 62 * q->dev_queue : It can test 63 * netif_xmit_frozen_or_stopped() before 64 * dequeueing next packet. 65 * Its true for MQ/MQPRIO slaves, or non 66 * multiqueue device. 67 */ 68 #define TCQ_F_WARN_NONWC (1 << 16) 69 #define TCQ_F_CPUSTATS 0x20 /* run using percpu statistics */ 70 #define TCQ_F_NOPARENT 0x40 /* root of its hierarchy : 71 * qdisc_tree_decrease_qlen() should stop. 72 */ 73 #define TCQ_F_INVISIBLE 0x80 /* invisible by default in dump */ 74 #define TCQ_F_OFFLOADED 0x200 /* qdisc is offloaded to HW */ 75 u32 limit; 76 const struct Qdisc_ops *ops; 77 struct qdisc_size_table __rcu *stab; 78 struct hlist_node hash; 79 u32 handle; 80 u32 parent; 81 82 struct netdev_queue *dev_queue; 83 84 struct net_rate_estimator __rcu *rate_est; 85 struct gnet_stats_basic_cpu __percpu *cpu_bstats; 86 struct gnet_stats_queue __percpu *cpu_qstats; 87 88 /* 89 * For performance sake on SMP, we put highly modified fields at the end 90 */ 91 struct sk_buff *gso_skb ____cacheline_aligned_in_smp; 92 struct qdisc_skb_head q; 93 struct gnet_stats_basic_packed bstats; 94 seqcount_t running; 95 struct gnet_stats_queue qstats; 96 unsigned long state; 97 struct Qdisc *next_sched; 98 struct sk_buff *skb_bad_txq; 99 int padded; 100 refcount_t refcnt; 101 102 spinlock_t busylock ____cacheline_aligned_in_smp; 103 }; 104 105 static inline void qdisc_refcount_inc(struct Qdisc *qdisc) 106 { 107 if (qdisc->flags & TCQ_F_BUILTIN) 108 return; 109 refcount_inc(&qdisc->refcnt); 110 } 111 112 static inline bool qdisc_is_running(const struct Qdisc *qdisc) 113 { 114 return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; 115 } 116 117 static inline bool qdisc_run_begin(struct Qdisc *qdisc) 118 { 119 if (qdisc_is_running(qdisc)) 120 return false; 121 /* Variant of write_seqcount_begin() telling lockdep a trylock 122 * was attempted. 123 */ 124 raw_write_seqcount_begin(&qdisc->running); 125 seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_); 126 return true; 127 } 128 129 static inline void qdisc_run_end(struct Qdisc *qdisc) 130 { 131 write_seqcount_end(&qdisc->running); 132 } 133 134 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc) 135 { 136 return qdisc->flags & TCQ_F_ONETXQUEUE; 137 } 138 139 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq) 140 { 141 #ifdef CONFIG_BQL 142 /* Non-BQL migrated drivers will return 0, too. */ 143 return dql_avail(&txq->dql); 144 #else 145 return 0; 146 #endif 147 } 148 149 struct Qdisc_class_ops { 150 /* Child qdisc manipulation */ 151 struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *); 152 int (*graft)(struct Qdisc *, unsigned long cl, 153 struct Qdisc *, struct Qdisc **); 154 struct Qdisc * (*leaf)(struct Qdisc *, unsigned long cl); 155 void (*qlen_notify)(struct Qdisc *, unsigned long); 156 157 /* Class manipulation routines */ 158 unsigned long (*find)(struct Qdisc *, u32 classid); 159 int (*change)(struct Qdisc *, u32, u32, 160 struct nlattr **, unsigned long *); 161 int (*delete)(struct Qdisc *, unsigned long); 162 void (*walk)(struct Qdisc *, struct qdisc_walker * arg); 163 164 /* Filter manipulation */ 165 struct tcf_block * (*tcf_block)(struct Qdisc *, unsigned long); 166 unsigned long (*bind_tcf)(struct Qdisc *, unsigned long, 167 u32 classid); 168 void (*unbind_tcf)(struct Qdisc *, unsigned long); 169 170 /* rtnetlink specific */ 171 int (*dump)(struct Qdisc *, unsigned long, 172 struct sk_buff *skb, struct tcmsg*); 173 int (*dump_stats)(struct Qdisc *, unsigned long, 174 struct gnet_dump *); 175 }; 176 177 struct Qdisc_ops { 178 struct Qdisc_ops *next; 179 const struct Qdisc_class_ops *cl_ops; 180 char id[IFNAMSIZ]; 181 int priv_size; 182 unsigned int static_flags; 183 184 int (*enqueue)(struct sk_buff *skb, 185 struct Qdisc *sch, 186 struct sk_buff **to_free); 187 struct sk_buff * (*dequeue)(struct Qdisc *); 188 struct sk_buff * (*peek)(struct Qdisc *); 189 190 int (*init)(struct Qdisc *, struct nlattr *arg); 191 void (*reset)(struct Qdisc *); 192 void (*destroy)(struct Qdisc *); 193 int (*change)(struct Qdisc *, struct nlattr *arg); 194 void (*attach)(struct Qdisc *); 195 196 int (*dump)(struct Qdisc *, struct sk_buff *); 197 int (*dump_stats)(struct Qdisc *, struct gnet_dump *); 198 199 struct module *owner; 200 }; 201 202 203 struct tcf_result { 204 union { 205 struct { 206 unsigned long class; 207 u32 classid; 208 }; 209 const struct tcf_proto *goto_tp; 210 }; 211 }; 212 213 struct tcf_proto_ops { 214 struct list_head head; 215 char kind[IFNAMSIZ]; 216 217 int (*classify)(struct sk_buff *, 218 const struct tcf_proto *, 219 struct tcf_result *); 220 int (*init)(struct tcf_proto*); 221 void (*destroy)(struct tcf_proto*); 222 223 void* (*get)(struct tcf_proto*, u32 handle); 224 int (*change)(struct net *net, struct sk_buff *, 225 struct tcf_proto*, unsigned long, 226 u32 handle, struct nlattr **, 227 void **, bool); 228 int (*delete)(struct tcf_proto*, void *, bool*); 229 void (*walk)(struct tcf_proto*, struct tcf_walker *arg); 230 void (*bind_class)(void *, u32, unsigned long); 231 232 /* rtnetlink specific */ 233 int (*dump)(struct net*, struct tcf_proto*, void *, 234 struct sk_buff *skb, struct tcmsg*); 235 236 struct module *owner; 237 }; 238 239 struct tcf_proto { 240 /* Fast access part */ 241 struct tcf_proto __rcu *next; 242 void __rcu *root; 243 int (*classify)(struct sk_buff *, 244 const struct tcf_proto *, 245 struct tcf_result *); 246 __be16 protocol; 247 248 /* All the rest */ 249 u32 prio; 250 u32 classid; 251 struct Qdisc *q; 252 void *data; 253 const struct tcf_proto_ops *ops; 254 struct tcf_chain *chain; 255 struct rcu_head rcu; 256 }; 257 258 struct qdisc_skb_cb { 259 unsigned int pkt_len; 260 u16 slave_dev_queue_mapping; 261 u16 tc_classid; 262 #define QDISC_CB_PRIV_LEN 20 263 unsigned char data[QDISC_CB_PRIV_LEN]; 264 }; 265 266 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv); 267 268 struct tcf_chain { 269 struct tcf_proto __rcu *filter_chain; 270 tcf_chain_head_change_t *chain_head_change; 271 void *chain_head_change_priv; 272 struct list_head list; 273 struct tcf_block *block; 274 u32 index; /* chain index */ 275 unsigned int refcnt; 276 }; 277 278 struct tcf_block { 279 struct list_head chain_list; 280 struct net *net; 281 struct Qdisc *q; 282 struct list_head cb_list; 283 struct work_struct work; 284 }; 285 286 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) 287 { 288 struct qdisc_skb_cb *qcb; 289 290 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz); 291 BUILD_BUG_ON(sizeof(qcb->data) < sz); 292 } 293 294 static inline int qdisc_qlen(const struct Qdisc *q) 295 { 296 return q->q.qlen; 297 } 298 299 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) 300 { 301 return (struct qdisc_skb_cb *)skb->cb; 302 } 303 304 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc) 305 { 306 return &qdisc->q.lock; 307 } 308 309 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc) 310 { 311 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc); 312 313 return q; 314 } 315 316 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) 317 { 318 return qdisc->dev_queue->qdisc_sleeping; 319 } 320 321 /* The qdisc root lock is a mechanism by which to top level 322 * of a qdisc tree can be locked from any qdisc node in the 323 * forest. This allows changing the configuration of some 324 * aspect of the qdisc tree while blocking out asynchronous 325 * qdisc access in the packet processing paths. 326 * 327 * It is only legal to do this when the root will not change 328 * on us. Otherwise we'll potentially lock the wrong qdisc 329 * root. This is enforced by holding the RTNL semaphore, which 330 * all users of this lock accessor must do. 331 */ 332 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc) 333 { 334 struct Qdisc *root = qdisc_root(qdisc); 335 336 ASSERT_RTNL(); 337 return qdisc_lock(root); 338 } 339 340 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 341 { 342 struct Qdisc *root = qdisc_root_sleeping(qdisc); 343 344 ASSERT_RTNL(); 345 return qdisc_lock(root); 346 } 347 348 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) 349 { 350 struct Qdisc *root = qdisc_root_sleeping(qdisc); 351 352 ASSERT_RTNL(); 353 return &root->running; 354 } 355 356 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) 357 { 358 return qdisc->dev_queue->dev; 359 } 360 361 static inline void sch_tree_lock(const struct Qdisc *q) 362 { 363 spin_lock_bh(qdisc_root_sleeping_lock(q)); 364 } 365 366 static inline void sch_tree_unlock(const struct Qdisc *q) 367 { 368 spin_unlock_bh(qdisc_root_sleeping_lock(q)); 369 } 370 371 extern struct Qdisc noop_qdisc; 372 extern struct Qdisc_ops noop_qdisc_ops; 373 extern struct Qdisc_ops pfifo_fast_ops; 374 extern struct Qdisc_ops mq_qdisc_ops; 375 extern struct Qdisc_ops noqueue_qdisc_ops; 376 extern const struct Qdisc_ops *default_qdisc_ops; 377 static inline const struct Qdisc_ops * 378 get_default_qdisc_ops(const struct net_device *dev, int ntx) 379 { 380 return ntx < dev->real_num_tx_queues ? 381 default_qdisc_ops : &pfifo_fast_ops; 382 } 383 384 struct Qdisc_class_common { 385 u32 classid; 386 struct hlist_node hnode; 387 }; 388 389 struct Qdisc_class_hash { 390 struct hlist_head *hash; 391 unsigned int hashsize; 392 unsigned int hashmask; 393 unsigned int hashelems; 394 }; 395 396 static inline unsigned int qdisc_class_hash(u32 id, u32 mask) 397 { 398 id ^= id >> 8; 399 id ^= id >> 4; 400 return id & mask; 401 } 402 403 static inline struct Qdisc_class_common * 404 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id) 405 { 406 struct Qdisc_class_common *cl; 407 unsigned int h; 408 409 if (!id) 410 return NULL; 411 412 h = qdisc_class_hash(id, hash->hashmask); 413 hlist_for_each_entry(cl, &hash->hash[h], hnode) { 414 if (cl->classid == id) 415 return cl; 416 } 417 return NULL; 418 } 419 420 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid) 421 { 422 u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY; 423 424 return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL; 425 } 426 427 int qdisc_class_hash_init(struct Qdisc_class_hash *); 428 void qdisc_class_hash_insert(struct Qdisc_class_hash *, 429 struct Qdisc_class_common *); 430 void qdisc_class_hash_remove(struct Qdisc_class_hash *, 431 struct Qdisc_class_common *); 432 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); 433 void qdisc_class_hash_destroy(struct Qdisc_class_hash *); 434 435 void dev_init_scheduler(struct net_device *dev); 436 void dev_shutdown(struct net_device *dev); 437 void dev_activate(struct net_device *dev); 438 void dev_deactivate(struct net_device *dev); 439 void dev_deactivate_many(struct list_head *head); 440 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 441 struct Qdisc *qdisc); 442 void qdisc_reset(struct Qdisc *qdisc); 443 void qdisc_destroy(struct Qdisc *qdisc); 444 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n, 445 unsigned int len); 446 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 447 const struct Qdisc_ops *ops); 448 void qdisc_free(struct Qdisc *qdisc); 449 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 450 const struct Qdisc_ops *ops, u32 parentid); 451 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 452 const struct qdisc_size_table *stab); 453 int skb_do_redirect(struct sk_buff *); 454 455 static inline void skb_reset_tc(struct sk_buff *skb) 456 { 457 #ifdef CONFIG_NET_CLS_ACT 458 skb->tc_redirected = 0; 459 #endif 460 } 461 462 static inline bool skb_at_tc_ingress(const struct sk_buff *skb) 463 { 464 #ifdef CONFIG_NET_CLS_ACT 465 return skb->tc_at_ingress; 466 #else 467 return false; 468 #endif 469 } 470 471 static inline bool skb_skip_tc_classify(struct sk_buff *skb) 472 { 473 #ifdef CONFIG_NET_CLS_ACT 474 if (skb->tc_skip_classify) { 475 skb->tc_skip_classify = 0; 476 return true; 477 } 478 #endif 479 return false; 480 } 481 482 /* Reset all TX qdiscs greater then index of a device. */ 483 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) 484 { 485 struct Qdisc *qdisc; 486 487 for (; i < dev->num_tx_queues; i++) { 488 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 489 if (qdisc) { 490 spin_lock_bh(qdisc_lock(qdisc)); 491 qdisc_reset(qdisc); 492 spin_unlock_bh(qdisc_lock(qdisc)); 493 } 494 } 495 } 496 497 static inline void qdisc_reset_all_tx(struct net_device *dev) 498 { 499 qdisc_reset_all_tx_gt(dev, 0); 500 } 501 502 /* Are all TX queues of the device empty? */ 503 static inline bool qdisc_all_tx_empty(const struct net_device *dev) 504 { 505 unsigned int i; 506 507 rcu_read_lock(); 508 for (i = 0; i < dev->num_tx_queues; i++) { 509 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 510 const struct Qdisc *q = rcu_dereference(txq->qdisc); 511 512 if (q->q.qlen) { 513 rcu_read_unlock(); 514 return false; 515 } 516 } 517 rcu_read_unlock(); 518 return true; 519 } 520 521 /* Are any of the TX qdiscs changing? */ 522 static inline bool qdisc_tx_changing(const struct net_device *dev) 523 { 524 unsigned int i; 525 526 for (i = 0; i < dev->num_tx_queues; i++) { 527 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 528 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) 529 return true; 530 } 531 return false; 532 } 533 534 /* Is the device using the noop qdisc on all queues? */ 535 static inline bool qdisc_tx_is_noop(const struct net_device *dev) 536 { 537 unsigned int i; 538 539 for (i = 0; i < dev->num_tx_queues; i++) { 540 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 541 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc) 542 return false; 543 } 544 return true; 545 } 546 547 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb) 548 { 549 return qdisc_skb_cb(skb)->pkt_len; 550 } 551 552 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */ 553 enum net_xmit_qdisc_t { 554 __NET_XMIT_STOLEN = 0x00010000, 555 __NET_XMIT_BYPASS = 0x00020000, 556 }; 557 558 #ifdef CONFIG_NET_CLS_ACT 559 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1) 560 #else 561 #define net_xmit_drop_count(e) (1) 562 #endif 563 564 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb, 565 const struct Qdisc *sch) 566 { 567 #ifdef CONFIG_NET_SCHED 568 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab); 569 570 if (stab) 571 __qdisc_calculate_pkt_len(skb, stab); 572 #endif 573 } 574 575 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, 576 struct sk_buff **to_free) 577 { 578 qdisc_calculate_pkt_len(skb, sch); 579 return sch->enqueue(skb, sch, to_free); 580 } 581 582 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 583 { 584 return q->flags & TCQ_F_CPUSTATS; 585 } 586 587 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats, 588 __u64 bytes, __u32 packets) 589 { 590 bstats->bytes += bytes; 591 bstats->packets += packets; 592 } 593 594 static inline void bstats_update(struct gnet_stats_basic_packed *bstats, 595 const struct sk_buff *skb) 596 { 597 _bstats_update(bstats, 598 qdisc_pkt_len(skb), 599 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1); 600 } 601 602 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 603 __u64 bytes, __u32 packets) 604 { 605 u64_stats_update_begin(&bstats->syncp); 606 _bstats_update(&bstats->bstats, bytes, packets); 607 u64_stats_update_end(&bstats->syncp); 608 } 609 610 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 611 const struct sk_buff *skb) 612 { 613 u64_stats_update_begin(&bstats->syncp); 614 bstats_update(&bstats->bstats, skb); 615 u64_stats_update_end(&bstats->syncp); 616 } 617 618 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch, 619 const struct sk_buff *skb) 620 { 621 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb); 622 } 623 624 static inline void qdisc_bstats_update(struct Qdisc *sch, 625 const struct sk_buff *skb) 626 { 627 bstats_update(&sch->bstats, skb); 628 } 629 630 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch, 631 const struct sk_buff *skb) 632 { 633 sch->qstats.backlog -= qdisc_pkt_len(skb); 634 } 635 636 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch, 637 const struct sk_buff *skb) 638 { 639 sch->qstats.backlog += qdisc_pkt_len(skb); 640 } 641 642 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count) 643 { 644 sch->qstats.drops += count; 645 } 646 647 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats) 648 { 649 qstats->drops++; 650 } 651 652 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats) 653 { 654 qstats->overlimits++; 655 } 656 657 static inline void qdisc_qstats_drop(struct Qdisc *sch) 658 { 659 qstats_drop_inc(&sch->qstats); 660 } 661 662 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch) 663 { 664 this_cpu_inc(sch->cpu_qstats->drops); 665 } 666 667 static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 668 { 669 sch->qstats.overlimits++; 670 } 671 672 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh) 673 { 674 qh->head = NULL; 675 qh->tail = NULL; 676 qh->qlen = 0; 677 } 678 679 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, 680 struct qdisc_skb_head *qh) 681 { 682 struct sk_buff *last = qh->tail; 683 684 if (last) { 685 skb->next = NULL; 686 last->next = skb; 687 qh->tail = skb; 688 } else { 689 qh->tail = skb; 690 qh->head = skb; 691 } 692 qh->qlen++; 693 qdisc_qstats_backlog_inc(sch, skb); 694 695 return NET_XMIT_SUCCESS; 696 } 697 698 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch) 699 { 700 return __qdisc_enqueue_tail(skb, sch, &sch->q); 701 } 702 703 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh) 704 { 705 struct sk_buff *skb = qh->head; 706 707 if (likely(skb != NULL)) { 708 qh->head = skb->next; 709 qh->qlen--; 710 if (qh->head == NULL) 711 qh->tail = NULL; 712 skb->next = NULL; 713 } 714 715 return skb; 716 } 717 718 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 719 { 720 struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); 721 722 if (likely(skb != NULL)) { 723 qdisc_qstats_backlog_dec(sch, skb); 724 qdisc_bstats_update(sch, skb); 725 } 726 727 return skb; 728 } 729 730 /* Instead of calling kfree_skb() while root qdisc lock is held, 731 * queue the skb for future freeing at end of __dev_xmit_skb() 732 */ 733 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free) 734 { 735 skb->next = *to_free; 736 *to_free = skb; 737 } 738 739 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch, 740 struct qdisc_skb_head *qh, 741 struct sk_buff **to_free) 742 { 743 struct sk_buff *skb = __qdisc_dequeue_head(qh); 744 745 if (likely(skb != NULL)) { 746 unsigned int len = qdisc_pkt_len(skb); 747 748 qdisc_qstats_backlog_dec(sch, skb); 749 __qdisc_drop(skb, to_free); 750 return len; 751 } 752 753 return 0; 754 } 755 756 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch, 757 struct sk_buff **to_free) 758 { 759 return __qdisc_queue_drop_head(sch, &sch->q, to_free); 760 } 761 762 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) 763 { 764 const struct qdisc_skb_head *qh = &sch->q; 765 766 return qh->head; 767 } 768 769 /* generic pseudo peek method for non-work-conserving qdisc */ 770 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) 771 { 772 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ 773 if (!sch->gso_skb) { 774 sch->gso_skb = sch->dequeue(sch); 775 if (sch->gso_skb) { 776 /* it's still part of the queue */ 777 qdisc_qstats_backlog_inc(sch, sch->gso_skb); 778 sch->q.qlen++; 779 } 780 } 781 782 return sch->gso_skb; 783 } 784 785 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ 786 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) 787 { 788 struct sk_buff *skb = sch->gso_skb; 789 790 if (skb) { 791 sch->gso_skb = NULL; 792 qdisc_qstats_backlog_dec(sch, skb); 793 sch->q.qlen--; 794 } else { 795 skb = sch->dequeue(sch); 796 } 797 798 return skb; 799 } 800 801 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh) 802 { 803 /* 804 * We do not know the backlog in bytes of this list, it 805 * is up to the caller to correct it 806 */ 807 ASSERT_RTNL(); 808 if (qh->qlen) { 809 rtnl_kfree_skbs(qh->head, qh->tail); 810 811 qh->head = NULL; 812 qh->tail = NULL; 813 qh->qlen = 0; 814 } 815 } 816 817 static inline void qdisc_reset_queue(struct Qdisc *sch) 818 { 819 __qdisc_reset_queue(&sch->q); 820 sch->qstats.backlog = 0; 821 } 822 823 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, 824 struct Qdisc **pold) 825 { 826 struct Qdisc *old; 827 828 sch_tree_lock(sch); 829 old = *pold; 830 *pold = new; 831 if (old != NULL) { 832 unsigned int qlen = old->q.qlen; 833 unsigned int backlog = old->qstats.backlog; 834 835 qdisc_reset(old); 836 qdisc_tree_reduce_backlog(old, qlen, backlog); 837 } 838 sch_tree_unlock(sch); 839 840 return old; 841 } 842 843 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 844 { 845 rtnl_kfree_skbs(skb, skb); 846 qdisc_qstats_drop(sch); 847 } 848 849 850 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch, 851 struct sk_buff **to_free) 852 { 853 __qdisc_drop(skb, to_free); 854 qdisc_qstats_drop(sch); 855 856 return NET_XMIT_DROP; 857 } 858 859 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how 860 long it will take to send a packet given its size. 861 */ 862 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen) 863 { 864 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead; 865 if (slot < 0) 866 slot = 0; 867 slot >>= rtab->rate.cell_log; 868 if (slot > 255) 869 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]; 870 return rtab->data[slot]; 871 } 872 873 struct psched_ratecfg { 874 u64 rate_bytes_ps; /* bytes per second */ 875 u32 mult; 876 u16 overhead; 877 u8 linklayer; 878 u8 shift; 879 }; 880 881 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r, 882 unsigned int len) 883 { 884 len += r->overhead; 885 886 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) 887 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift; 888 889 return ((u64)len * r->mult) >> r->shift; 890 } 891 892 void psched_ratecfg_precompute(struct psched_ratecfg *r, 893 const struct tc_ratespec *conf, 894 u64 rate64); 895 896 static inline void psched_ratecfg_getrate(struct tc_ratespec *res, 897 const struct psched_ratecfg *r) 898 { 899 memset(res, 0, sizeof(*res)); 900 901 /* legacy struct tc_ratespec has a 32bit @rate field 902 * Qdisc using 64bit rate should add new attributes 903 * in order to maintain compatibility. 904 */ 905 res->rate = min_t(u64, r->rate_bytes_ps, ~0U); 906 907 res->overhead = r->overhead; 908 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK); 909 } 910 911 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc. 912 * The fast path only needs to access filter list and to update stats 913 */ 914 struct mini_Qdisc { 915 struct tcf_proto *filter_list; 916 struct gnet_stats_basic_cpu __percpu *cpu_bstats; 917 struct gnet_stats_queue __percpu *cpu_qstats; 918 struct rcu_head rcu; 919 }; 920 921 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq, 922 const struct sk_buff *skb) 923 { 924 bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb); 925 } 926 927 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq) 928 { 929 this_cpu_inc(miniq->cpu_qstats->drops); 930 } 931 932 struct mini_Qdisc_pair { 933 struct mini_Qdisc miniq1; 934 struct mini_Qdisc miniq2; 935 struct mini_Qdisc __rcu **p_miniq; 936 }; 937 938 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp, 939 struct tcf_proto *tp_head); 940 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc, 941 struct mini_Qdisc __rcu **p_miniq); 942 943 #endif 944